Do You Know The Cloud Forest?

A cloud forest, also called a fog forest, is a generally tropical or subtropical evergreen montane moist forest characterized by a persistent, frequent or seasonal low-level cloud cover, usually at the canopy level. Cloud forests often exhibit an abundance of mosses covering the ground and vegetation, in which case they are also referred to as mossy forests. Mossy forests usually develop on the saddles of mountains, where moisture introduced by settling clouds is more effectively retaine.

Dependent on local climate, which is affected by the distance to the sea, the exposition and the latitude, the altitude varies from 500 m to 4000 m above sea level. Typically, there is a relatively small band of altitude in which the atmospheric environment is suitable for cloud forest development. This is characterized by persistent mist or clouds at the vegetation level, resulting in the reduction of direct sunlight and thus of evapotranspiration. Within cloud forests, much of the precipitation is in the form of fog drip, where fog condenses on tree leaves and then drips onto the ground below.

Tropical cloud forests extend from 23°N to 25°S latitudes and occur in a relatively narrow altitudinal zone with a special atmospheric environment which is characterized by at the vegetation level. Annual rainfall can range from 500 to 10,000 mm/year and mean temperature between 8 to 20 °C.

While cloud forest today is the most widely used term, in some regions these ecosystems or special types of cloud forests are called mossy forest, elfin forest, montane thicket, dwarf cloud forest, nuboselva, bosque montano nebuloso, selva de neblina, bosque nuboso, bosque de ceja, selva sublada, nebelwald, wolkenwald, forêt néphéliphile, forêt de nuage, unmu-rin, bosque anao, foresta nebular, mata nebular, matinha nebular, floresta fe neblina, floresta nuvigena, mata de neblina, matinha de altitude, floresta nublada, and floresta pluvial montana e/ou alto montana.

The definition of cloud forest can be ambiguous, with many countries not using the term (preferring such terms as Afromontane forest and upper montane rain forest, montane laurel forest, or more localised terms such as the Bolivian yungas, and the laurisilva of the Atlantic Islands),and occasionally subtropical and even temperate forests in which similar meteorological conditions occur are considered to be cloud forests.Only 1% of the global woodland is covered by cloud forests.

Although far from being universally accepted as true cloud forests, several forests in temperate regions have strong similarities with tropical cloud forests. The term is further confused by occasional reference to cloud forests in tropical countries as "temperate" due to the cooler climate associated with these misty forests.

In comparison with lower tropical moist forests, cloud forests show a reduced tree stature combined with increased stem density and generally the lower diversity of woody plants.Trees in these regions are generally shorter and more heavily stemmed than in lower altitude forests in the same regions, often with gnarled trunks and branches, forming dense, compact crowns. Their leaves become smaller, thicker and harder with increasing altitude.The high moisture promotes the development of a high biomass and biodiversity of epiphyte, particularly bryophytes, lichens, ferns (including filmy ferns), bromeliads and orchids.The number of endemic plants can be very high.

An important feature of cloud forests is that the tree crowns can intercept the wind-driven cloud moisture, part of which drips to the ground. This water stripped from the clouds is termed horizontal or occult (because it is not recorded with normal rainfall measurement) precipitation, and can be an important contribution to the hydrologic cycle.

Due to the high water content of the soil, the reduced solar radiation and the low rates of decomposition and mineralization, the soil acidity is very high,with more humus and peat often forming the upper soil layer.